258 
An example of an alluvial soil is given below. The sample 
was taken from the banks of the Mahaweli-ganga at Peradeniya : 
ANALYSIS OF ALLUVIAL SOIL, EXPERIMENT STATION, PERADENIYA. 
Mechanical Composition. 
Per Cent. 
Fine soil passing 90 mesh 53-9° 
Fine soil passing 60 mesh • 43. 00 
Medium soil passing 30 mesh 3. 00 
Coarse sand and small stones 0.10 
100.00 
Chemical Composition. 
Moisture 3.000 
Organic matter and combined water 11. 000 
Oxide of iron and manganese 8.000 
Oxide of alumina 9-7 l 7 
Lime o. 130 
Magnesia 0.259 
Potash 0.162 
Phosphoric acid 0.076 
Soda o. 188 
Sulphuric acid 0-054 
Chlorine 0.014 
Sand and silicates 67.400 
100.000 
Containing nitrogen 0.230 
Equal to ammonia 0.280 
Lower oxide of iron Much 
Acidity Neutral 
Citric soluble potash 0.013 
Citric soluble phosphoric acid Trace 
The sample is a micaceous loamy deposit in a fine state of divi- 
sion with a fair retentive power of moisture. There is a fairly 
good supply of organic matter with a good supplv of nitrogen. 
The acidity, as it is to be expected, from such a soil is nil. The 
mineral plant food is good in lime, magnesia, and potash, mainly 
derived from the mica, but is rather poor in phosphoric acid. 
3. Tea and Cacao Soils. — On many estates the tea and cacao 
has been interplanted with rubber, and the variation in soil com- 
position is very great. 
The following analyses show the composition of tea and cacao 
land now planted with rubber, and the latter showing a good 
growth in the Peradeniya district : 
